In recent years, light emitting diode (LED) light sources, as a new generation of green energy-saving light sources, have been widely used. An LED light source can serve as a light source for plant growth due to its characteristics such as small volume and power conservation.
Inventors have found that at least following problems exist in the prior art: at present, most light sources of this type in the market can provide light irradiation only, but cannot achieve an automatic control of timed lighting and lighting-off; furthermore, in LED light sources in the present market, there is no transition process of brightness change from lighting to lighting-off and from lighting-off to lighting, so the LED light sources in the present market do not match with the actual natural light, and thus cannot fully simulate natural light.